QUROPE Quantum Information Processing and Communication in Europe

Location

PhD position: Trapped ions in optical microtraps

We are looking for a highly-motivated student with excellent laboratory skills for performing state-of-the-art atomic physics experiments.

The hybrid atom-ion quantum systems lab, headed by Dr. Rene Gerritsma, is part of the Quantum Gases and Quantum Information (QGQI) cluster at the University of Amsterdam. The main focus of the group is to study the quantum dynamics in trapped ions while at the same time developing technology for emerging quantum applications, such as quantum computing and simulation.

In the project you will develop a new quantum simulation platform: trapped ions that are pinned by optical microtraps. Simulating quantum systems on classical computers is extremely hard, as the resources required scale exponentially with system size. This limitation prevents physicists from testing whether microscopic model Hamiltonians of solid-state physics such as the Fermi-Hubbard model correctly predict emergent phenomena in many-body quantum systems (e.g., magnetic phases and phase transitions, superconductivity). Richard Feynman proposed to solve this problem by having well-controlled laboratory quantum systems simulate quantum problems of interest. Such quantum simulators would be the quantum analogue of a wide range of simulators of complex classical physics, ranging from crash test dummies to numerical weather-prediction software. Over the years, a number of laboratory quantum systems have been put to the test as a platform for quantum simulation. Trapped ions are among the most reliable of these systems and several groups have shown impressive progress in trapped ion quantum simulation.

You will answer two questions:

1) Can we scale up the trapped ion further by using two-dimensional ion crystals?

2) Can we use optical microtraps to tune the soundwave spectrum in the crystal and use these to simulate quantum magnets?

Since spin-spin interactions between ions are mediated via sound waves, they are very long ranged, as there is no screening of charge in the ion crystal. However, many models that are of interest to quantum simulate require shorter-ranged interaction. In the project, we will pin particular ions in the crystal with optical microtraps to modify the soundwave spectrum such that short range spin-spin interactions become available. These can be used to quantum simulate models of frustrated spin systems that are particularly hard to simulate on classical computers.

Relevant references:

• R. Nath, M. Dalmonte, A. W. Glaetzle, P. Zoller, F. Schmidt-Kaler and R. Gerritsma,
  New J. Phys. 17, 065018 (2015).
• Zhang, G. Pagano, P. W. Hess, A. Kyprianidis, P. Becker, H. B. Kaplan, A. V. Gorshkov,
  Z.-X. Gong, and C. Monroe, Nature 551, 601 (2017).

To apply go to this website, for further information contact r [dot] gerritsma [at] uva [dot] nl">Rene Gerritsma